RPL second impressions (HP 28)

[Thomas Klemm]

(06-29-2018 07:35 PM)Gerson W. Barbosa Wrote:  Also, your version is faster: 201 seconds for testing 177777773 instead of 214 seconds (on the real 28S).

This variant raises an error when a divisor is found:

Code:

«
  IF DUP 2 MOD
  THEN → n
    «
      IFERR 3 n √
        FOR d
          IF n d MOD NOT
          THEN 0 DOERR
          END
          2
        STEP
      THEN 0
      ELSE 1
      END
    »
  ELSE NOT
  END
»

My hope is that using a FOR-loop is both faster and easier to understand.